Engine conversions for offroad vehicles are popular with both old & new models. We have been involved with engine and transmission conversions for more than 40 years and are not surprised when we see a new vehicle with less than 10,000 miles having an engine swapped. Since you are venturing out beyond the boundary of the corner gas station and local repair shop, you should be aware that offroad driving is quite different than street driving. Once you pull onto a dirt road, your vehicle must be capable of returning you and your passengers back to civilization. The best, single reason for an offroad 4WD engine conversion is reliability. If your 4WD cannot deliver this, then you're in serious trouble. Make sure that when making a change on your offroad vehicle it is done with the best equipment and design available. Don't short change your conversion for components that will give you less reliability.
There will always be situations where more power would be nice such as when towing a trailer, turning those big new tires, or falling short from the top of a hill. A common mistake of many offroad drivers is overpowering the existing drivetrain. If additional power is required and the stock transmission specifications and rear axle torque rating have been exceeded, then you might be required to use a stronger substitute. Jeeps have been equipped with several types and sizes of engines. In order to assist you, we have listed the various stock engines that were used in the 1980s & newer vehicles.
151 CID 4 Cylinder (1980-83) Iron Duke
150 CID 4 Cylinder Engine (1984-86)
150 CID 4 Cylinder Engine TBI (1987-02)
148 CID 4 Cylinder Engine (2.4) (2003-04)
258/4.2L CID Straight 6 Cylinder (1972-90)
4.0L Straight 6 Cylinder (1991-04)
2.8L V6 Engine (Cherokees) (1984-86) GM
2.5L V6 Engine 151 CID (XJ) (1984-00) GM
304 CID V8 Engine (1972-81)
4.0L Engine (XJ) (1987-01)
2.4L & 3.7L Engine (KJ) (2002-04)
Select a motor which best fits the use of your vehicle. We manufacture motor mounts, bellhousing adapters, headers, and transfer case adapters for Chevy, Chevy Vortec V8's, Ford, Dodge, Buick V6 & some AMC motors. Within these range of motors, every practical need can be met.
Many people become overly concerned about moving the transmission, resulting in driveshaft modifications. The value of a good engine location requiring driveshaft modifications will far exceed the expenses of an installation requiring special cooling due to poor engine location.
We design most transfer case adapters to eliminate driveshaft modifications (whenever possible). In order to position your new engine, it is usually mandatory that the original engine mounts be removed from the chassis. When placing the new motor into the chassis, several factors determine the best possible location.
A. Firewall Clearance: Allow adequate clearance between the distributor & firewall. Be sure that the distributor can be removed easily. Make sure the engine can be worked on without having to remove it from the vehicle.
B. Front Axle Clearance: Check the oil pan and harmonic balancer for axle housing clearance. Double check the suspension clearance if bottoming out. Location of the motor mounts will require some vehicles to relocate their front axle snubber.
C. Hood Clearance: When the air cleaner is in position, will the hood still close? On certain applications, special low profile air cleaners may be required.
D. Driveshaft Clearance & Angularity: The front driveshaft should have sufficient clearance to pass the bellhousing and starter. When using a transmission other than what was stock, front driveshaft clearances may be an issue. The drivetrain should be offset 1â€ to the driver's side to obtain additional front driveshaft clearance. Make sure that the driveshafts do not bottom out when the suspension is collapsed. The angle of the rear driveshaft is very critical, and compensation can be made by either axle shims or lowering the transfer case.
E. Radiator Clearances: Proper spacing and centering of the fan with the radiator is necessary for optimum cooling. If you are having a problem in this area, an alternative is an electric cooling fan. These fans are popular for engine conversions, since they can be mounted on the front or backside of the radiator and don't require engine placement considerations when using an engine-driven fan.
F. Exhaust Manifold/Header Clearance: If headers are planned for the vehicle, it is best to purchase them before the installation of the engine. Although we make headers for several different applications, a perfect fit can never be guaranteed. When locating the engine, have the headers or stock manifolds in place and check the following for clearances: firewall, brake & clutch pedals through travel, steering box or linkage, body & frame, heater/defroster, and battery. When placing the engine into position, be sure and have your engine exhaust system mounted on the engine. This ensures all proper clearances are maintained.
G. Oil Filters: Oil filters can be a real problem especially on Ford conversions. The filter on Ford engines is locate up front on the driver's side, and this can interfere with the stock steering or suspension components. If additional clearance is needed, we suggest a remote oil filter. We offer remote oil filter kits for most engines.
H. Motor Mount Installation: The motor mounts we manufacture are designed for specific applications, along with some universal applications. Some are a bolt-in style, while others require welding. The universal mounts are designed to fit a variety of frame widths. The channels that extend to the block are slotted, allowing choice of engine placement. CJ7 eng conv
â€œLâ€ brackets on weld-in mounts should be welded entirely around the perimeter. All welding should be done by a certified welder. When using a double donut design mount, make sure that the donuts properly index to the â€œLâ€ bracket and the bolts are properly tightened. Mount bolts should be checked periodically.
I. Steering Shaft: Most stock 4WD engines are offset to the driver's side 1/2" to 1â€ to line up the transfer case and differential yoke and we recommend the new engine have a offset to the drivers side on these Jeeps. This normally does not present any clearance issues with the stock steering shaft. We have found that as these Jeep get older, the stock steering shaft does develop end play. We now carry heavy duty replacement steering shafts for Jeep 1980 to 1986. Jeep's original steering shaft assembly was not designed for the added stress of body lifts and oversize tires. We carry the Borgeson's replacement assembly's which have a telescoping shaft with two precision needle bearing u-joints. The steering assembly is easy to install with common hand tools. Once installed, you will experience much tighter and more responsive steering.
P/N 716869 75-86 CJ STEERING SHAFT MANUAL BOX
P/N 716870 75-86 CJ STEERING SHAFT POWER BOX
Once the engine has been selected, you will now need engine mounts. We offer several combinations that will fit Ford, Chevy, Dodge, and Buick blocks. On most Ford and Chevy applications, we standardize our mounts by using a special dual rubber donut, locked together with special hardened bolts. This combination offers a positive means of securing the engine for the most severe offroad conditions.
Most of our mounts are universal and can be adjusted to accommodate the best possible engine location, while others are very specific and offer no alternate for changes. Our universal Chevy and Ford side mounts are the most popular style for Jeep engine conversions. The mounts are furnished so that they can be either welded or bolted into position, and are fully adjustable so that the engine can be offset.
The universal mounts are now available in two styles; one for the Jeep universals, and one for the wider framed vehicles that will fit up to 30.500" frames. In the Buick V6 category, we also offer a universal Buick V6 engine mount that utilize our double donut design and is fully adjustable, similar to the Chevy and Ford engine mounts. This mount is PN713011, and does not require the use of the original Buick V6 rubbers.
In conjunction with all engine mounts, you will need to use a rear crossmember mount. This is usually the same mount with a new location adjusted to the new engine position. Two mounting points are all that is ever required with most installations. This will allow for plenty of engine flexibility and will eliminate transmission and engine vibrations.
We have been doing engine conversions for over 40 years . We've learned the hard way to count only on top-quality & proven design installations. Our mounts are secured with a 5/8â€ diameter bolt between the engine brace and frame bracket. No rubber vulcanization failure will let you down. To assure that you have the premier engine mounts that we offer, make sure our name is on the box. Do not accept look-a-like takeoffs.
Universal Motor Mounts: The universal mounts we manufacture are a high quality mounting system. The â€œLâ€ brackets in these kits are made out of 3/8â€ material and designed to handle any style of driving. These universal mounts allow for lateral and vertical placement in the frame rail to maximize you drivetrain fit. The installation of these mounts will require the removal of you stock engine mounts. CJ7, 713007 OFFSET
PN713007 -1972-1986 Jeep universal and Jeep Wagons/Trucks Chevy V8 motor mounts
PN713005 -1972-1986 Jeep universal and Jeep Wagons/Trucks Chevy V8 LT1 motor mounts
PN713088 -1976-1986 Jeep CJ7 Chevy V8 Gen III & LS1 motor mounts
PN713006 -1972-1986 Jeep universal and Jeep Wagons/Trucks Ford small block V8 motor mounts
PN713011 -1972-1986 Jeep universal and Jeep Wagons/Trucks Buick V6 motor mounts
PN713095 -1972-1986 Jeep universal and Jeep Wagons/Trucks Dodge V8 (318/360) motor mounts
Stock Rubber Support Motor Mounts: We also offer motor mounts designed to utilize the stock engine rubber mounts. These type of engine mounts are a good alternative to the universal type if you need to replace a rubber support. Most auto parts stores can supply you with a stock rubber support. We offer only two mounting systems this way; one for the Chevy block and one for the AMC V8 engines.
PN713089 -1976-1986 Jeep CJ7 bolt-in Chevy V8 motor mounts
PN713120 -1980-1986 Jeep universal and Jeep Wagons/Trucks AMC V8 (304/360/401) motor mounts
Chevy LS1 Blocks and Vortec Generation III Universal Mounts: We offer a universal weld-in mount. 713088 is a weld-in mount that uses a double donut rubber insulator. This mount should not be used in a Jeep TJ. These mounts will interfere with the Generation III LS1 stock manifolds.
We also offer a mount plate that adapts the square bolt pattern to a triangular bolt pattern. This plate positions the triangular bolt pattern in the same block location as that of the early GM mount. This mount will work with most stock GM configurations. PN713088-P